This research was developed with the goal to evaluate the river-head of the hydrographic microbasin at Grilo stream, concerning its conservation state, soil usage and surrounding vegetation aspects. Its main target is to support recovery and preservation acts, evolving sources and riparian vegetation. The study has been carried out in the hydrographic microbasin at Grilo stream, which belongs to Piauitinga river hydrographic sub-basin, located at Boquim and Salgado counties, Sergipe. To identify the river-head were used a map from the region and a GPS device, as well a local inhabitant s aid. The river-head characterization was done considering the conservation state (preserved, disturbed or degraded), water source type (punctual or diffuse), soil usage and most prevalent disturbances in the area. Other sorts of information collected were: specific location, property owner s name and geographical coordination. Out of 65 river-head identified at the remarked area, 95,38% are degraded, 3,08% are disturbed and 1,54% preserved. Concerning the type of water source, punctual sources (66,15%) have been identified more frequently than diffuse ones (33,85%). Most registered kinds of disturbances were weed (48,19%), presence of domestic animals (48,83%) and clear cutting of vegetation (44,19%). Most representative soil usages found are livestockfarming (55,81%) and permanent farming (46,51%). Along vegetation screening, some sources have been selected: three of those among punctually degraded (PDe) and diffusely degraded (DDe) categories, and one among diffusely disturbed (DDi) and punctually disturbed (PDi) categories, where 4 plots of 500m² (10x50m) have been distributed, and the individuals at breast height diameter (DAP at 1,30m from the soil surface) ≥ 5,0cm were measured. The parameters evaluated were: density, dominance, frequency, relevance index, Shannon-Weaver s diversity index (H ), Pielou s equability index (J ), and Jaccard s index (Sj) to evaluate forest resemblance among the river-head. As for local forest diversity, sites which are diffusely concerned in general (62) presented more sorts of species than punctually degraded (33), as well as degraded ones (59) own greater diversity than disturbed ones (32). Referring to sucessional state of vegetation, there has been recorded a majority of climax light-demanding species, in every category studied. Relating to forest resemblance, water source sites have been divided in three groups (PDi1/DDi1/DDe1; PDe1/PDe2/PDe3/DDe2 and DDe3). Species diversity and richness reached greater numbers at the diffusely degraded category. As a result of the studies developed at the Grilo stream hydrographic microbasin and its importance to the region, it is notorious that it requires urgent recovery attitudes evolving these river-head sites. As for phytossociological analysis, some species have shown more capacity to adapt to the conditions of the studied environments (dry and flooded areas), an information that should be taken in account when planning river-head and water streams recovery programs. / Este trabalho foi realizado com o objetivo de avaliar as nascentes da microbacia hidrográfica do riacho Grilo, quanto ao estado de conservação, usos do solo e vegetação no entorno dessas áreas, visando dar suporte às ações de recuperação e preservação de nascentes e margens de cursos d água. O estudo foi realizado na microbacia hidrográfica do riacho Grilo, pertencente à sub-bacia hidrográfica do rio Piauitinga, nos municípios de Boquim e Salgado, Sergipe. Para a identificação das nascentes em campo utilizou-se uma carta da microbacia hidrográfica e aparelho GPS, contando também com o auxílio de um morador da região. Para a caracterização, as nascentes foram avaliadas quanto ao estado de conservação (preservada, perturbada e degradada), tipo de reservatório (pontual ou difusa), usos do solo e principais perturbações ocorrentes nas áreas. Ainda foram registradas informações como localização (município e povoado), nome do proprietário e atual coordenada geográfica. De 65 nascentes identificadas na microbacia hidrográfica do riacho Grilo, 95,38% encontram-se degradadas, 3,08% perturbadas e 1,54% preservadas. Com relação ao tipo de recarga, foram identificadas mais nascentes pontuais (66,15%) que difusas (33,85%). Os tipos de perturbações mais encontrados foram plantas invasoras (48,83%), presença de animais domésticos (48,83%) e corte raso da vegetação (44,19%). Os usos do solo mais representativos foram: pecuária (55,81%) e lavouras permanentes (46,51%). Para o levantamento da vegetação foram selecionadas três nascentes nas categorias degradada pontual (DP) e degradada difusa (DD), e uma nas categorias perturbada difusa (PD) e perturbada pontual (PP), onde foram instaladas 4 parcelas de 500m2 (10x50m), sendo amostrados os indivíduos com diâmetro à altura do peito (DAP a 1,30m do solo) ≥ 5,0cm. Os parâmetros avaliados foram: densidade, dominância, freqüência, índice de valor de importância, índice de diversidade de Shannon-Weaver (H ) e eqüabilidade de Pielou (J ), além do índice de Jaccard (Sj) para avaliar a similaridade florística entre as nascentes. Na composição florística das nascentes estudadas na microbacia hidrográfica do riacho Grilo, as difusas apresentaram mais espécies (62) que as pontuais (33), assim como as degradadas (59) mais que as perturbadas (32). Quanto à classificação sucessional, em todas as categorias de nascentes houve predominância de espécies clímax exigentes em luz. Em relação à similaridade florística entre as nascentes, houve a separação em três grupos (PP1/PD1/DD1; DP1/DP2/DP3/DD2 e DD3). A categoria com maiores valores de riqueza e diversidade de espécies foi a degradada difusa. Diante do que foi estudado nas nascentes da microbacia hidrográfica do riacho Grilo e da importância que este representa para a região, é notória a necessidade de adoção de medidas urgentes para recuperação dessas áreas. Na análise fitossociológica foi possível identificar espécies que mostraram-se mais adaptadas aos ambientes seco e alagado, devendo-se seguir essa recomendação em programas de recuperação de nascentes e cursos d água.

Made available in DSpace on 2016-12-23T14:37:30Z (GMT). No. of bitstreams: 1 Lucas Contarato Pilon.pdf: 1648966 bytes, checksum: cac40ef638ed16eaccc0afa53f321565 (MD5) Previous issue date: 2013-02-28 / Diante da necessidade de obter informações sobre o cultivo de cafeeiros arborizados, o objetivo do trabalho é avaliar a relação dos atributos químicos, físicos e os componentes da matéria orgânica do solo sob cultivo de café consorciado com diferentes espécies arbóreas, comparativamente ao café cultivado a pleno sol, tendo como referência uma área sob floresta. O trabalho foi conduzido em sistemas de produção de café, numa propriedade familiar, município de Nova Venécia - ES. O solo da área é um ARGISSOLO AMARELO Distrocoeso típico, cultivado com café conilon consorciado com árvores, nos seguintes sistemas de uso e manejo: 1) café sem consórcio (pleno sol), 2) café consorciado com nim (Azadirachta indica), 3) café consorciado com cedro australiano (Cedrela fissilis) e 4) café consorciado com teca (Tectona grandis). Foi utilizado um solo de área florestal, como referência. A amostragem do solo foi realizada nas seguintes profundidades: 0,0 0,05; 0,05 0,10; 0,10 0,20; e 0,20 0,40 m, avaliando-se atributos químicos (pH, P, K, Ca, Mg, Al, H+Al, N, C total, C ext em água, C biomassa microbiana e emissão de CO2) e físicos do solo (granulometria, densidade do solo e de partículas, porosidade total, macro e microporosidade, estabilidade de agregados, resistência do solo à penetração e umidade do solo). A avaliação do carbono solúvel (C ext) e do carbono da biomassa microbiana do solo (CBMS) foi realizada em duas épocas (março e setembro/2012) nas profundidades de 0,0 0,05 e 0,05 0,10 m; já a emissão de CO2 foi medida na mesma época que, na presença e ausência de serapilheira. Os resultados experimentais mostram que os sistemas de uso e manejo apresentam comportamento diferenciado para grande parte dos atributos estudados. O solo florestal apresenta maiores teores e estoques de carbono orgânico total e nitrogênio total, 19,8 e 1,99 Mg ha-1 respectivamente, além de maior teor de carbono na biomassa microbiana (518,8 μg g-1 solo em março e 364,8 μg g-1 solo em setembro). Os atributos dos solos sob cafeeiros consorciados, de maneira geral, não diferem do solo sob cafeeiro a pleno sol, exceção feita para os atributos Mg, N e o C ext, C-BMS, quociente microbiano (qMic) na duas épocas de coleta, os quais são superiores nos consórcios agroflorestais, e o quociente metabólico (qCO2) inferior, denotando maior estabilidade dos cafeeiros arborizados. O café a pleno sol mostra-se um agroecossitema mais perturbado com maior qCO2 (1,81 μg CO2 C-BMS-1 h-1 em março e 2,44 μg CO2 C-BMS-1 h-1 em setembro). A proteção do solo ocasionada pelo sombreamento das árvores e a deposição de serapilheira influencia principalmente os atributos biológicos estudados, favorecendo um maior equilíbrio nos cafeeiros arborizados. Com relação aos atributos físicos, o consórcio proporciona menor densidade do solo, maior porosidade total e macroporosidade do solo, diferindo do café a pleno sol. Os cafeeiros consorciados se diferem somente na agregação do solo. A resistência do solo à penetração é influenciada pela umidade do solo, com destaque para o café a pleno sol que apresenta valores mais baixos desse atributo, em função da irrigação, que eleva a umidade do solo. O estudo numa condição de Argissolo coeso, mostra que 5 anos de implantação de sistemas arborizados são suficiente para apresentar pequenas mudanças nos atributos estudados, no entanto para atributos de alta sensibilidade, como os biológicos, são suficientes para apresentar mudanças mais consistentes dos sistemas de uso e manejo / Faced with the need for information on the coffee agroforestry systems, the objective is to evaluate the relationship of the chemical, physical and components of soil organic matter under coffee intercropping with different tree species, compared to the full-sun coffee with an area under forest like reference. The research was conducted in coffee production systems, a family farm, in Nova Venécia city - ES. The soil is an YELLOW ULTISOL Distrocohesive typical, with shadow coffee plantation, the following different land use systems and management: 1) coffee full (full-sun), 2) coffee intercropped with neem (Azadirachta indica), 3) coffee intercropped with Australian cedar (Cedrela fissilis) and 4) coffee intercropped with Teca (Tectona grandis). It was used a soil of forest area, as a reference. Soil sampling was conducted in the following depths: 0.0-0.05, 0.05-0.10; 0.10-0.20, and 0.20-0.40 m, evaluating chemical soil attributes ( pH, P, K, Ca, Mg, Al, H + Al, total nitrogen (TN), total organic carbon (TOC), water-soluble carbon (WSC), soil microbial biomass carbon (SMBC) and soil CO2 emission and physical soil attributes (particle size, bulk density, total porosity, macroporosity, microporosity and soil resistance penetration), was collected and characterization of accumulated litter. The evaluation of soluble carbon (soluble C) and soil microbial biomass carbon (SMBC) was held twice a year (March and september/2012) at depths from 0.0-0.05 and 0.05-0, 10 m, the soil CO2 emission was measured at the same times, in the presence and absence of litter. The experimental results show that the use and management systems were characterized for most attributes researched. The forest soil has higher levels of stocks and TOC and TN, 19.8 and 1.99 Mg ha-1 respectively, and the higher SMBC (518.8 mg g-1 soil in March and 364, 8 mg g-1 soil in September). The soil under shadow coffee, in general, do not differ from full-sun coffee, except for the attributes Mg, N and soluble C, SMBC, microbial quotient (QMIC) at both harvests, which are higher in agroforestry systems, and attributes TOC/ soluble C and metabolic quotient (qCO2) lower values, indicating greater stability of shadow coffee systems. The full-sun coffee shows more disturbed agroecosystem with high qCO2 (1.81 μg CO2 CBMS-1 h-1in March and 2.44 μg CO2 CBMS-1 h-1 in September). The protection of soil caused by shading from trees and litterfall influences the biological attributes primarily, favoring a greater balance in shadow coffee. Relative to physical attributes, the intercropped provides a lower bulk density, higher total porosity and macroporosity, differing full-sun coffee. The shadow coffee up differs only in soil aggregation. The soil resistance penetration is influenced by soil moisture, especially for full-sun coffee which shows lower values of this attribute, depending on irrigation management, which increase soil moisture. The study provides a ULTISOL cohesive, shows that 5 years of systems implementation, are enough to present small changes in the attributes studied, however high sensitivity to attributes such as biological changes are sufficient to represent most consistent use and management systems

<p>U&nbsp; radu&nbsp; je&nbsp; prikazana&nbsp; distribucija,&nbsp; dinamika&nbsp; i&nbsp; diverzitet&nbsp; insekata opra&scaron;ivača iz reda Hymenoptera&nbsp; -&nbsp; Apiformes (Anthophila) i Diptera Syrphidae)&nbsp; na&nbsp; stepskim&nbsp; fragmentima&nbsp; i&nbsp; na&nbsp; suncokretu&nbsp; u agroekosistema&nbsp; Vojvodine.&nbsp; U&nbsp; cilju&nbsp; uvida&nbsp; u&nbsp; strukturu&nbsp; predela&nbsp; injenog&nbsp; uticaja&nbsp; na&nbsp; sastav&nbsp; i&nbsp; brojnost&nbsp; polinatora,&nbsp; kartirani&nbsp; su&nbsp; tipovistani&scaron;ta&nbsp; oko&nbsp; svakog&nbsp; stepskog&nbsp; fragmenta.&nbsp; Na&nbsp; osnovu&nbsp; podataka dobijenih kartiranjem, odabrano je sedam stepskih fragmenata kojiu&nbsp; svom&nbsp; okruženju&nbsp; imaju&nbsp; visok&nbsp; udeo&nbsp; suncokreta&nbsp; kao&nbsp; masovnocvetajuće&nbsp; kulture&nbsp; i&nbsp; sedam&nbsp; stepskih&nbsp; fragmenata&nbsp; koji&nbsp; su&nbsp; bez&nbsp; ili&nbsp; saniskim&nbsp; udelom&nbsp; suncokreta.&nbsp; Iz&nbsp; reda&nbsp; Hymenoptera&nbsp; &ndash;&nbsp; Apoideazabeleženo&nbsp; je&nbsp; &scaron;est&nbsp; familija:&nbsp; Andrenidae,&nbsp; Apidae,&nbsp; Colletidae,Halictidae,&nbsp; Melittidae&nbsp; i&nbsp; Megachilidae,&nbsp; 114&nbsp; vrsta,&nbsp; a&nbsp; iz&nbsp; reda&nbsp; Diptera(Syrphidae),&nbsp; registrovano&nbsp; je&nbsp; ukupno&nbsp; 11&nbsp; vrsta.&nbsp; Predstavnici&nbsp; familija Andrenidae, Apidae i Halictidae su distribuirani na svim lokalitetima,predstavnici&nbsp; familije&nbsp; Megachilidae&nbsp; su&nbsp; distribuirani&nbsp; na&nbsp; 15&nbsp; od&nbsp; 16lokaliteta,&nbsp; a&nbsp; najmanje&nbsp; su&nbsp; zastupljene&nbsp; jedinke&nbsp; familija&nbsp; Colletidae&nbsp; i<br />Melittidae,&nbsp; distribuirane&nbsp; na&nbsp; pet&nbsp; lokaliteta.&nbsp; Polinatori&nbsp; reda&nbsp; Diptera familije&nbsp; Syrphidae&nbsp; su&nbsp; distribuirani&nbsp; na&nbsp; svim&nbsp; lokalitetima.&nbsp; Rezultati Kruskal-Volisovog H testa ukuzuju da je tokom sve tri sezone (2011.,2012.,&nbsp; 2013.)&nbsp; na&nbsp; stepskim&nbsp; fragmentima&nbsp; najvi&scaron;e&nbsp; bilo&nbsp; zastupljeno vrsta&nbsp; solitarnih&nbsp; pčela,&nbsp; zatim&nbsp; vrsta&nbsp; osolikih&nbsp; muva,&nbsp; a&nbsp; najmanje&nbsp; vrsta bumbara.&nbsp; Istim&nbsp; testom&nbsp; je&nbsp; dobijano&nbsp; da&nbsp; je&nbsp; tokom&nbsp; sve&nbsp; tri&nbsp; sezone&nbsp; na stepskim&nbsp; fragmentima,&nbsp; registrovano&nbsp; najvi&scaron;e&nbsp; jedinki&nbsp; osolikih&nbsp; muva,<br />zatim&nbsp; medonosne&nbsp; pčele,&nbsp; solitarne&nbsp; pčele,&nbsp; a&nbsp; najmanje&nbsp; jedinki bumbara.&nbsp; Fridmanovim&nbsp; testom&nbsp; su&nbsp; utvrđene&nbsp; razlike&nbsp; u&nbsp; brojnosti (dinamici)&nbsp; polinatora&nbsp; kroz&nbsp; sezone,&nbsp; uočen&nbsp; je&nbsp; porast&nbsp; broja&nbsp; jedinki medonosne pčele i opadanje broja jedinki solitarnih pčela.Rezultati&nbsp; dobijeni&nbsp; Man-Vitnijevim&nbsp; U-testom&nbsp; pokazuju&nbsp; da&nbsp; je&nbsp; na<br />stepskim&nbsp; fragmentima&nbsp; koji&nbsp; imaju&nbsp; niži&nbsp; udeo&nbsp; suncokreta&nbsp; u&nbsp; predelu zastupljeno&nbsp; vi&scaron;e&nbsp; jedinki&nbsp; i&nbsp; vrsta&nbsp; bumbara.&nbsp; Istim&nbsp; testom&nbsp; je&nbsp; dobijen rezultat&nbsp; da&nbsp; je&nbsp; na&nbsp; stepskim&nbsp; fragmentima&nbsp; sa&nbsp; visokim&nbsp; udelom suncokreta&nbsp; ima&nbsp; vi&scaron;e&nbsp; jedinki&nbsp; medonosne&nbsp; pčele.&nbsp; Vilkoksonovim testom&nbsp; sume&nbsp; rangova&nbsp; je&nbsp; pokazano&nbsp; da&nbsp; su&nbsp; jedinke&nbsp; i&nbsp; vrste&nbsp; bumbara zastupljenije na stepskim fragmentima nakon cvetanja suncokreta, za&nbsp; vreme&nbsp; cvetanja&nbsp; suncokreta&nbsp; na&nbsp; stepskim&nbsp; fragmentima&nbsp; je registrovano&nbsp; vi&scaron;e&nbsp; jedinki&nbsp; <em>Apis&nbsp; mellifera</em>,&nbsp; osolikih&nbsp; muva&nbsp; i&nbsp; solitarnih pčela.&nbsp; Modeli&nbsp; regresionih&nbsp; analiza&nbsp; linearnih&nbsp; me&scaron;ovitih&nbsp; modela&nbsp; su pokazali&nbsp; da&nbsp; se&nbsp; sa&nbsp; porastom&nbsp; udela&nbsp; suncokreta&nbsp; u&nbsp; predelu&nbsp; smanjuje broj jedinki divljih pčela i jedinki i vrsta bumbara. Sa porastom udela polu-prirodnih&nbsp; stani&scaron;ta&nbsp; u&nbsp; predelu&nbsp; i&nbsp; većom&nbsp; cvetnom&nbsp; pokrovnosti, povećava se udeo jedinki i vrsta osolikih muva.</p> / <p>This&nbsp; paper&nbsp; shows&nbsp; distribution,&nbsp; dynamic&nbsp; and&nbsp; pollinator&nbsp; diversity Hymenoptera&nbsp; -&nbsp; Apiformes&nbsp; (Anthophila)&nbsp; and Diptera (Syrphidae)&nbsp; in semi-natural&nbsp; habitats&nbsp; and&nbsp; in&nbsp; sunflower&nbsp; crops&nbsp; in&nbsp; Vojvodina&nbsp; agroecosystems.&nbsp; Around&nbsp; each&nbsp; of&nbsp; 16&nbsp; selected&nbsp; steppe&nbsp; fragments,&nbsp; habitat types&nbsp; were&nbsp; mapped&nbsp; to&nbsp; test&nbsp; how&nbsp; do&nbsp; landscape&nbsp; structure&nbsp; affects pollinator&nbsp; diversity&nbsp; and&nbsp; abundance&nbsp; in&nbsp; semi&nbsp; natural&nbsp; habitats&nbsp; and&nbsp; in sunflower&nbsp; crops.&nbsp; Based&nbsp; on&nbsp; the&nbsp; results&nbsp; obtained&nbsp; by&nbsp; mapping,&nbsp; seven study sites with high % of sunflower like mass flowering crops, and eight&nbsp; study&nbsp; sites&nbsp; with&nbsp; no&nbsp; or&nbsp; low&nbsp; %&nbsp; of&nbsp; mass&nbsp; flowering&nbsp; crops&nbsp; are selected. In total, there were 114 species from 6 families&nbsp; from order Hymenoptera-Apiformes:&nbsp; Andrenidae,&nbsp; Apidae,&nbsp; Colletidae, Halictidae, Melittidae and Megachilidae, and 11 species from order Diptera&nbsp; (Syrphidae).&nbsp; Insects&nbsp; from&nbsp; families:&nbsp; Andrenidae,&nbsp; Apidae, Colletidae&nbsp; and&nbsp; Halictidae&nbsp; were&nbsp; distributed&nbsp; on&nbsp; all&nbsp; study&nbsp; sites,&nbsp; while insects&nbsp; from&nbsp; family&nbsp; Megachilidae&nbsp; were&nbsp; distributed&nbsp; almost&nbsp; on&nbsp; all study&nbsp; sites&nbsp; (15&nbsp; sites).&nbsp; At&nbsp; least&nbsp; only&nbsp; on&nbsp; five&nbsp; study&nbsp; sites&nbsp; were distributed insects from family: Colletidae and Melittidae. Hoverflies were distributed on all study sites.&nbsp; Kruskal-Wallis H test shows that an&nbsp; all&nbsp; three&nbsp; seasons&nbsp; (2011.,&nbsp; 2012.,&nbsp; 2013.)&nbsp; in&nbsp; semi&nbsp; natural&nbsp; habitats wild bees species were most abundant, followed by hoverfly species, and bumblebee species at the end. Same test&nbsp; shows that&nbsp; in all three seasons in semi natural habitats individuals of hoverflies were more abundant than individuals of honey bees, wild bees&nbsp; and individuals of&nbsp; bumblebees,&nbsp; which&nbsp; were&nbsp; least&nbsp; abundant.&nbsp; Friedman&nbsp; test&nbsp; shows differences in densities of pollinator through the seasons, and these results&nbsp; shows&nbsp; increasing&nbsp; in&nbsp; Apis&nbsp; mellifera&nbsp; densities&nbsp; and&nbsp; decline&nbsp; of wild bees densities through seasons. Man-Whitney&nbsp; U-test&nbsp; shows&nbsp; that&nbsp; there&nbsp; were&nbsp; more&nbsp; species&nbsp; and individuals of bumble bees in semi-natural habitats which landscapes are without&nbsp; or low % of sunflower. Same test shows that there were more&nbsp; individuals&nbsp; of&nbsp; honey&nbsp; bees&nbsp; in&nbsp; semi-natural&nbsp; habitats&nbsp; which landscapes&nbsp; have&nbsp; high&nbsp; %&nbsp; of&nbsp; sunflower.&nbsp; Wilcoxon&nbsp; signed-rank&nbsp; test shows&nbsp; that&nbsp; in&nbsp; semi-natural&nbsp; habitats&nbsp; species&nbsp; and&nbsp; individuals&nbsp; of bumblebees&nbsp; were&nbsp; more&nbsp; abundant&nbsp; after&nbsp; blooming&nbsp; sunflower,&nbsp; while species&nbsp; and&nbsp; individuals&nbsp; of&nbsp; wild&nbsp; bees&nbsp; as&nbsp; well&nbsp; as&nbsp; individuals&nbsp; of hoverflies and&nbsp; <em>Apis mellifera</em>&nbsp; were&nbsp; more abundant during blooming sunflower.&nbsp; Linear mixed-effect model shows that with increase of % of&nbsp; sunflower&nbsp; in&nbsp; landscape&nbsp; number&nbsp; of&nbsp; individuals&nbsp; of&nbsp; wild&nbsp; bees&nbsp; and species and individuals of bumblebees decreasing, and individuals of hoverflies increasing. With an increase of % of semi natural habitats and&nbsp; increase&nbsp; of&nbsp; flower&nbsp; cover,&nbsp; abundance&nbsp; and&nbsp; species&nbsp; of&nbsp; hoverflies<br />increases.</p>

The development of human societies rests on functioning ecosystems. This thesis builds on integrated theories of linked social-ecological systems and complex adaptive systems to increase the understanding of how to strengthen the capacity of ecosystems to generate services that sustain human well-being. In this work, I analyze such capacity in human-dominated production ecosystems in Tanzania and Madagascar, and how this capacity is related to local management practices. Resilience of social-ecological systems refers to the capacity to buffer change, to re-organize following disruption, and for adaptation and learning. In Papers I and II, qualitative interview methods are used for mapping and analyses of management practices in the agroecosystem of the Mbulu highlands, Northern Tanzania. Practices such as soil and water conservation, maintenance of habitats for pollinators and predators of pests, intercropping, and landscape diversification, act to buffer food production in a variable environment and sustain underlying ecological processes. The practices are embedded in a decentralized but nested system of institutions, such as communal land rights and social networks, that can buffer for localized disturbances such as temporary droughts. Paper II compares these findings with practices in a farming system in Sweden, and suggests that similar mechanisms for dealing with uncertainty and change can exist in spite of different biophysical conditions. In Papers III and IV, interviews are combined with GIS tools and vegetation sampling to study characteristics and dynamics of the dry forests of Androy, southern Madagascar. Paper III reports on a previously underestimated capacity of the dry forest of southern Madagascar to regenerate, showing areas of regeneration roughly equal areas of degenerated forest (18 700 ha). The pattern of forest regeneration, degradation, and stable cover during the period 1986-2000 was related to the enforcement of customary property rights (Paper III). Paper IV reports on a network of locally protected forest patches in Androy that is embedded in a landscape managed for agricultural or livestock production and contributes to the generation of ecosystem services and ecosystem resilience at a landscape scale. Forest protection is secured by local taboos that provide a well-functioning and legitimate sanctioning system related to religious beliefs. In Paper V, two spatial modeling tools are used to assess the generation of two services, crop pollination and seed dispersal, by the protected forest patches in southern Androy. The functioning of these services is dependent on the spatial configuration of protected patches in the fragmented landscape and can be highly vulnerable to even small changes in landscape forest cover. In conclusion, many of the identified practices are found to make ecological sense in the context of complex systems and contribute to the resilience of social-ecological systems. The thesis illustrates that the capacity of human-dominated production ecosystems to sustain a flow of desired ecosystem services is strongly associated with local management practices and the governance system that they are embedded in, and that, contrary to what is often assumed, local management can and does add resilience for desired ecosystem services. These findings have substantial policy implications, as insufficient recognition of the dynamics of social-ecological interactions is likely to lead to failure of schemes for human development and biodiversity conservation.

Predatory Ground beetles (Coleoptera: Carabidae) and Lady beetles (Coleoptera: Coccinellidae) are two of the most diverse groups found in wheat agroecosystems, globally. These groups are important from both an economic and ecological perspective due to their natural services provision. The effect of wheat agroecosystem management on species diversity, abundance, biomass and composition in South Africa is not yet documented, and there is no existing data indicating which predatory carabid and coccinellid species provides essential ecosystem services and bioindicator roles. Therefore, we examined the effects of organic, conventional and intercropped agroecosystems on ground beetle and lady beetle abundance, dried weight (biomass), composition and diversity. Sampling of wheat agroecosystems was conducted in three systems i.e. organic, conventional and organic intercropped. Post-hoc Tukey test indicated a statistically significant difference between species diversity, biomass and abundance in organic and intercropped systems compared to the conventional systems. Regression analysis indicated significant positive correlation between aphid’s density and predatory carabid and coccinellid beetles in the intercropped systems. Amongst the weather factors temperature influenced aphid density and carabid and coccinellid beetles’ abundance. PCA (Principal Component Analysis) revealed significant positive correlation between individual biomass and cropping system. Conventional system showed a negative correlations with carabid and coccinellid individual biomass. We found that some carabid and coccinellid species can be used to measure the quality of agroecosystems. This study provides a fundamental basis for identification and monitoring of carabid and coccinellid species and their role as bioindicators of ecological disturbance. The identified bioindicator species in this study can assist in developing conservation and biomonitoring strategies within agroecosystems. / Agriculture and  Animal Health / M. Sc. (Agriculture)